Method of applying protective material to road surfaces



Oct. 6, 1936. H. E. CUMMINGS I 2,055,258

METHOD OF APPLYING-PROTECTIVE MATERIAL TO ROAD SURFACES Filed Sept. 7', 195:5

INVENTOK HQI'UE Cummizgs.

ditty.

Patented Oct. 6, 1936 UITED STATES PATENT OFFICE METHOD OF APPLYING PROTECTIVE MATERIAL TO ROAD SURFACES 6 Claims.

This invention deals, in general terms, with highway construction, having particular reference to their maintenance and preservation.

Specifically, it involves a method of operation 5 related directly to oiling or otherwise treating the surface of highways which, from their nature or character, are susceptible of such treatment. The invention varies from present-day practice in the n matter of application of the protective material 1'0"" to the road surface.

My method is particularly well adapted for use in that type of road construction in which gravel forms a major portion of the'roadbed section,,or

in other types, such as concrete, over which it is 15' desired to spread a thin coating of the oily material or tar products to ,make it impervious to Water.

In the foregoing classes ofroads it is common practice, at stated periods, to cover the surface with a low grade of oil and to immediately thereafter spread a thin layer of fine sand over the oil which, eventually, is taken up and absorbed by the'sand. .In certain instances a drag or levelling device is'drawn over the oil and sand-treated surface, but in any event the usual traffic over the road finally rolls the material into a more or less com pact protective covering which greatly assists in preventing erosion and guttering' by rain storms and dissipation of much of the road surface to the sides of the road, during dry weather, by each passing vehicle raising the dust and waiting it to either side. These difficulties are bound to'occur p, even when a road is well built but does not receive 5" proper care thereafter; and His the primary object of the present invention to improve onthe present method of protecting its surface once the road has been properly constructed.

While my present conception contemplates the 40' use of oil and sand as the protective materials generally employed for this purpose, it is in the manner or method of applying them that the nov-' elty of the invention mainly consists.

' The primary object sought' in my invention is to reduce the yearly expenditure of funds required to satisfactorily protect a road surface after once being properly built. It is due to the high cost of oiling a road that many municipalities are unable, from lack of ample funds, to properly care for them. And anything which will alleviate. the

situation is worthwhile.

With this end in View I have conceived a plan embodying a method calculated to reduce the cost ofmaterial used for protecting the road surface by a considerable amount, the method consisting in applying the oil in stretches alternating with bare portions of the road surface.

.It is a well known fact that motor vehicle tires rollingover freshly oiled and sanded roads pick up and carry forward considerable amounts of 5 these materials. Thus when the tires pass off the oiled and sanded stretches a portion of this material is carried along on to the bare stretches, and in the course of a short period of time it will be found that there is sufficient protective material distributed over the originally bare surface to satisfactorily cover it for protection purposes, Ample evidence that trafiic distributes this oilsand mixture is found by observation of two intersecting roads, one only of which is oil treated. For some distance on the untreated road the oil will be found, carried there by traflic passing thereonto from the oil treated one.

, The alternating, oiled and bare, stretches may be arranged in various ways, a preferred arrange- 2o ment being to divide the road into two longitudinal lanes, operating first on one and then on the other, the oiled stretches being staggered with respect to the two lanes.

In carrying out my invention in practice it is 25 possible to use the present tank truck oil control equipment to manually operate the opening and closing of the oil distributing valve, but I prefer, for reasons of procuring greater accuracy and uniformity in distribution of the oil, to equip the truck with a. simple mechanism, acting wholly automatically, with provision to vary the period of time during which the oil is discharging so as to obtain various proportionate lengths of oiled and bare stretches, respectively. 5

Such a device, illustrative in character, is depicted in the accompanying drawing in which also is shown various arrangements of protective coverings respecting their allocation on the road surface. 40

I In the drawing, in which similar reference characters are employed to identify like parts in the various views thereof,-

'Fig. 1 represents a two-lane highway, the oiled surfaces thereon being shown in shaded portions and separated by bare spaces;

Fig, 2 shows a single lane road with respect to the oiled surface, the oiled stretches being arranged across the full width of the highway;

Fig. .3 illustrates an alternative method of depositing the oil; in this instance-it is laid in narrow longitudinal strips with bare spaces intervening;

Fig; It shows, fragmentarily, an oil distributing truck with apparatus installed thereon for autoof a roadbed divided, with respect to the oiling?? thereof, into two lanes, the oiling operation being conducted first on one side of the" center line .r-x, and then on the other.

On each lane there are stretches of oiledsur faces I alternating with somewhat shorter stretches of bare surfaces 2. It will be observed that the oiled surfaces on one lane are staggered with respect to those on the other lane. This brings the bare spaces 2, taking the two lanes together, into somewhat closer relation, relatively, than if the oil was distributed in a manner depicted in Fig. 2, by reason of the fact that vehicles cutting out of line or operated in amore or less promiscuous manner -zig-zagging, as it werewill cause the oil to be more quickly and completely spread over these bare portions.

Allocating the oiled stretchesin the manner shown in Fig. 2 will give very satisfactory re sults particularly where the road is narrow and illustrative in character, embodying an automatically operating mechanism which may be installed on an oil tank truck for accurately laying the protective material in separated stretches over the road surface, as illustrated in Figs. 1 5.: and 2. t

An oil tank 3 is mounted on a truck frame 4, and the axle 5 of the runninglgear carries-a sprocket wheel 6. chain"! the sprocket wheel 8 is driven,- the latter being fixed on the transversely disposed shaft 9.

Secured to the shaft 9 is a cam l0 engaging which isa roll ll mounted on the reciprocable plunger l2. The opposite end of the plunger is connected to one arm l3 of'abell crank lever and the other arm Id of theleyer 'actuates the valve rod'i5, on the lower end of which is a valve [6. Raising the valve from its seat I! permits oil 'to fiow from the oil-conducting tube [8 into a chamber l9 located within the long, transversely extending box 20. From this box depend a plu rality of nozzles 2| on the lower ends of which are sprinkler heads 22 which deliver the oil to the road surface through'smallapertures 22a.

The oil tube i8 is directly connected ,to the tank 3.

In the foregoing description of theoil-contro1 mechanism a gravity fee'd arrangement is contemplated. A forced ejection of the oil may be, and more than likely would be employed. Ap-

I paratus of this character is shown in abbreviated form in Fig. 6 of the drawing;

In this forced-feedmethod of delivering the oil the cam l0, through the intermediary ele.-.

ments, including the lever 24 pivoted at 25,, op

erates a clutch 26 which when engaged withits Throughthe, agency of, the.

for oil pumping purposes. When the clutch is disengaged the pump is idle. The forced feed pumping unit is equipped with oil tubes 18a and nozzles 22b.

. Referring to Fig. 5 it will be observed that there are shown two index arcuate lines indicating and identifying the dwells on the cam ID, the dwell a being the longer and serving with the connecting parts to open the valve Hi. When the roll II passes ofi" the dwell a on to the dwell b the valve is closed through the agency of the spring [6a. '.1 The arcs a. and b represent, relatively, the open and close times of the valves 16, but they also represent the proportional lengths of the oiled and bare surfaces of the roadbed after the oil has beenlaid thereover.

Different proportionate lengths of oiled and bare stretches may be obtained by changing the rim.,l0a..of the cam l0. Examples of this can be seen by reference to Figs. 7 and 8. While I have shown a simple method of driving the cam l0, namely, by sprockets and chain, it is of course quite obvious that a system of interchangeable gearing might be employed. After it is first determined what lengths of oiled and bare stretches are desirable, the proper reduction in gearing to open and close the oil discharge valve at the proper times is easily found.

' It might be thought that the same objects could be attained by applying the oil in a thinner coating but overthe entire surface of the roadbed. This would not, however, be feasible since it is absolutely essential that the oil be laid in a sufficiently thick layer or coating to enable the sand to be completely impregnated with it. Furthermore, should there'not be enough oil to thor oughly saturate the sand, the outer or dry portion would be dissipated by passing traffic and be blown off the highway. In other words, wherever the'oil is. deposited it should be in such quantities as to form a proper binder for the sand, and a too thin application will not serve the purpose.

The condition of the roadbed surface will largely determine'the proportionate lengths of the respective stretches of treated and bare surfaces. The, looser the bare stretches the'shorter they will'be, and the firmer or more compact these, portions are,'the longer they may be.

As has previously been stated, the primary objectof my invention is to conserve material used for road preservation and dust-laying purposes, and I have elected to illustrate and describe it in connection with the use of oil and sand as the protective mediums solely for the purpose of comprehensively disclosing it.

I do not, therefore, wish it understood that I limit or restrict. myself to. the, use of these substances as I am not concernedfwith the material itself but only with the method or manner of applying it to road surfaces.

For instance, certain kinds of tar products, if

heated, could be distributed over the road surface in the manner hereinbefore set forth for oil; and a saving in material could easily be effected.

Then, too, if the object be simply to lay the dust on the roadbed, certain chemical products, such as calcium chloridefmight be employed to carry out my invention, the only requirement being to provide a proper apparatus which, as in the case with the oil, could lay the material in separated stretches, And as the chemical mentioned has. a strong, aflinity for moisture it would readily lend itself for the p rpose required and mosteffectively be carried on vehicle tires from the treated portions on to the bare sections of the roadbed.

What I claim is:

1. A method of applying protective material to road surfaces consisting of depositing oil and sand upon the surface in separated areas, the bare, intervening spaces being of such length as will insure being covered by the oil and sand mixture incident to and through the agency of vehicular traflic over the highway.

2. A method of treating already constructed roads which consists in applying to the road surface an unctuous material laid in longitudinally separated areas extending substantially the full width of the roadbed, and immediately thereafter spreading a thin layer of sand over the unctuous material, the sand, together with the unctuous material being carried from the respective treated areas on to the bare, intervening areas by the wheels of vehicles passing over the highway in both directions, to the end that the protective covering laid in segregated portions may subsequently merge into a continuous covering of the road surface.

3. A method of treating roads consisting in applying to the road surface an oily substance, flowed thereonto and left in longitudinally spaced areas extending for a predetermined portion of the width of the roadbed, and then spreading over the treated areas a granular substance adapted to absorb the oily substance and be carried by vehicular trafiic on to the intervening bare spaces lying between the oil-treated portions of the road surface, whereby the bare areas may subsequently be covered by the protective covering, comprising the oily and granular substances.

4. A method of protecting roads having a loose top surface consisting in depositing on said surface over areas longitudinally and predeterminately spaced, an unctuous material, and immediately following this operation, spreading a layer of a granular substance adapted to absorb the unctuous material and to be carried by vehicular trafiic on to and cover the bare intervening spaces, whereby the whole length of the highway, originally intermittently covered by protective material, may become covered by a continuous stretch of the said covering material through the agency of vehicular traflic over said highway. i

5. A method of applying protective material to road surfaces consisting in depositing thereon a coating of oily material and subsequently covering the oily material with a thin layer of sand, the oily material being laid over the full width of the road surface in stretches longitudinally alternating with bare spaces the lengths of which are uniform and determined by the capacity of vehicular traific to pick up and carry thereonto portions of the oily material and sand first deposited, whereby eventually the entire surface of theroad will receive protective covering.

6. A method of protecting road surfaces consisting in depositing thereon a coating of oily material at short distances apart along the highway, and then covering the oily material with a thin layer of sand, the intervening bare stretches being predeterminate in length but no longer than will insure being subsequently covered by a portion of the originally deposited oil and sand carried on to the bare spaces by vehicular trafiic in both directions, the proportionate lengths of the oil-and-sand covered and bare spaces depending on the condition of the road surface and varying from five to one, respectively.

HARRY E. CUIWMINGS. 

